Arai blasted home runs in consecutive bats against the Yomiuri Giants on April 12, 2017. It was the twenty-second time he hit two home runs in one game over his career, first since July 12, 2016. At forty years and two months, he is the second player in Hiroshima Carp history over forty to accomplish the feat. The other was Sachio Kinugasa on June 14, 1987 at forty years and four months.

Arai recorded a pinch-hit, come-from-behind, three-run home run with two out in the ninth inning of a game against the Yakult Swallows at Jingu Stadium on May 7, 2017.

At forty-years and five months, he became the oldest player in Hiroshima Carp franchise history to record a pinch-hit home run. The previous record of thirty-nine years and ten months was set by Koji Yamamoto on September 11, 1986. Forty-seven home runs have now been hit by players over forty in NPB history. He is the first to record a pinch-hit, come-from-behind home run in the ninth inning with two out.

The pinch-hit home run was the eleventh of his career (tenth in a Hiroshima uniform).